820240888440 has 128 divisors (see below), whose sum is σ = 2498159520000. Its totient is φ = 215405042688.

The previous prime is 820240888403. The next prime is 820240888447. The reversal of 820240888440 is 44888042028.

It is a self number, because there is not a number n which added to its sum of digits gives 820240888440.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820240888447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 32943516 + ... + 32968404.

It is an arithmetic number, because the mean of its divisors is an integer number (19516871250).

Almost surely, 2^820240888440 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 820240888440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1249079760000).

820240888440 is an abundant number, since it is smaller than the sum of its proper divisors (1677918631560).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

820240888440 is a wasteful number, since it uses less digits than its factorization.

820240888440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29069 (or 29065 counting only the distinct ones).

The product of its (nonzero) digits is 1048576, while the sum is 48.

The spelling of 820240888440 in words is "eight hundred twenty billion, two hundred forty million, eight hundred eighty-eight thousand, four hundred forty".